In this Slides definition,types and manufacturing of Ready Mixed Concrete(RMC) has been discussed. This will be of great help to the students of civil engineering. They will find it more handy and easily understandable. This will also help to Teachers and professionals.

1. Ready Mixed Concrete
Prepared By
Gourhari Biswas,

2. Ready Mixed Concrete (RMC)
• Ready Mixed Concrete is a tailor – made
concrete that is manufactured in a factory
or within a batching plant based on the
standard required specifications. The
prepared concrete mix is then taken to the
work site within transit mixers mounted
over a truck.
• Ready mixed refers to concrete that is
batched for delivery from a central plant
instead of being mixed on the job site.

3. Uses of Ready Mixed Concrete
• It is used in the construction of bridge, dam etc.
• It is used in the construction overhead roads,
pools, multi-storied building etc.
• It can bedirectly used at the construction site.
• It help greater element of automation and
precision concrete mixing.
• A much higher quality and more constituent
uniformity and increase standardization and
speed which is done ten times faster as
compared to site mixed concrete.

4. Advantages of Ready Mixed Concrete
• Quality concrete is obtained as a ready-mix concrete mix
plant make use of sophisticated equipment and
consistent methods. There is strict control over the
testing of materials, process parameters and continuous
monitoring of key practices during the manufacture.Poor
control on the input materials, batching and mixing
methods in the case of site mix concrete is solved in a
ready-mix concrete method.
• Speed in the construction practices followed in ready mix
concrete plant is followed continuously by having
mechanised operations. The output obtained from a site
mix concrete plant using a 8/12 mixer is 4 to 5 metric
cubes per hour which is 30-60 metric cubes per hour in a
ready mix concrete plant.

5. Advantages of Ready Mixed Concrete contd...
• Better handling and proper mixing practice will help to
reduce the consumption of cement by 10 – 12%. Use of
admixtures and other cementitious materials will help to
reduce the amount of cement.
• The concrete mixed is used with high versatility. It is
placed by following best concrete placing methods.
• Cement is saved and the dust caused is reduced as
ready mix concrete make use of bulk concrete instead of
bags of cement.
• Cement saving will conserve the energy and the
resources.
• Less consumption result in less production of cement
hence less environmental pollution.
• More durable structure is obtained thus increasing the
service life and saving the life cycle costs.

6. contd...
• Ready mix concrete manufacture have less dependency
on human labours hence the chances of human errors is
reduced. This will also reduce the dependency on
intensive labours.
• Small or large quantities of concrete as per the
specification is delivered timely at the site.
• This demands no space for storing the raw materials at
site. There is no delay due to site based batching plant
erection/ dismantling; no equipment to hire; no
depreciation of costs.
• Petrol and diesel consumed is less thus noise and air
pollution is reduced.
• Better quality concrete is produced as it is made from
consistent methods and in advanced equipment.

7. Advantages of Ready Mixed Concrete contd...
•

8. Disadvantages of Ready Mixed Concrete
 The transit time from the time of preparation of concrete
to the delivery site, will result in loss of workability. This
will demand for additional water or admixtures to
maintain the workability as per the specification.
 Traffic during the transit of concrete can result in setting
of concrete. This will hence require addition of
admixtures to delay the setting period. But unexpected
traffic is a great problem
 Requires huge initial investment.
 Not suitable for small projects (less quantity of concrete
is required).
 Need an effective transportation system from the
batching plant to the job site.

9. Types of Ready-Mix-Concrete
There are three
types in ready-mix
concrete:
Transit mixed
concrete
Shrink-mixed
concrete
Central-mixed
concrete

10. Transit mixed concrete
• It is also known as truck
mixed concrete, in which
materials are batched at a
central plant and are
thoroughly mixed in the
truck in transition.
• Transit-mixing avoids the
problems of early hardening
and slump loss that result in
delays in transportation.

11. Shrink-mixed concrete
 In this type , concrete is
partially mixed in a stationary
mixer at the ready mix plant.
The final mixing is done in a
truck mixer enroute to the job.
 It is used to increase the truck's
load capacity where concrete is
mixed at the plant to shrink the
volume of the concrete.
 The balance mixing of concrete
is completed in the truck during
transit time or at the
construction site.

12. Central-mixed concrete
• Sometimes, the central mixed
plants are referred to as wet
batch plants. The concrete is
batched and completely
mixed in a stationary mixer at
the plant site before
discharging it into the truck
mixers.
• The advantages of central-
mixed concrete are better
quality control, consistency,
higher production capability
and reduce wear on the truck
mixer drums.
Stationery Batching
Plant

13. Batching and Mixing of Ready Mixed Concrete
Stationary Mixing of
Concrete
Stationary Mixers are used onsite or
Central Mix R/M plant. It is used for
complete or shrink mixing. The
concrete mixer can mix up to 9m3.
It can have tilting or non-tilting drum,
open top revolving blade or paddle.
Typical complete mixing times of
this machine is minimum of 1 min.
for up to 1 m3 or less mixer capacity
plus 15 seconds for each additional
m3 or fraction thereof.
Control room for batching
equipment

14. Truck Mixed Concrete
Truck Mixed
Concrete
It requires 70 to 100
revolutions required for
mixing. Mixing speed varies
from 6 to 18 rpm. After
mixing, drum revolves at
agitating speed, 2 to 6 rpm.
The concrete needs to be
discharged before
exceeding 300 drum
revolutions and before 1½
hours.

15. Transporting and Handling of Ready Mixed
Concrete
Wheelbarrows and
Buggies
These are used for
short flat hauls on all
types of onsite concrete
construction. its
advantages: Versatile—
ideal inside and on
jobsites with changing
placing conditions. This
method is slow and
labor intensive.

16. Belt Conveyor
It is used for conveying
concrete horizontally or
higher/lower level.
Advantages: Adjustable
reach, traveling diverter,
variable speed. End-
discharge arrangements
needed to prevent
segregation and mortar on
return belt. Belt cover
needed in hot and
windy weather.

17. Truck Mounted Conveyors
It is used for conveying
concrete horizontally or
higher/lower level.
Advantages: Conveyer
arrives with concrete.
Adjustable reach and
variable speed. Watch for:
End-discharge
arrangements needed to
prevent segregation and
mortar on return belt. Belt
cover needed in hot and
windy weather.

18. Buckets
I

19. Cranes and Buckets
It is used for work
above ground level.
Its advantages: Can
handle concrete,
reinforcing steel,
formwork, and
sundry items.

20. Pump
Pumps are used for conveying
concrete from central
discharge point to formwork.
Its advantages: Pipelines take
up little space and can be
readily extended. Delivers
concrete in continuous stream.
Pump can move. Watch for:
Constant supply of freshly-
mixed concrete is needed
without any tendency to
segregate.

21. What is Concrete Pump?
A Concrete Pump truck is a tool
that is used for conveying or
carrying the freshly mixed
liquid concrete from the
containers or the batching
plants to the construction sites
where it needs to be casted or
filled.
A concrete pump is a very
important tool for the big
construction projects for
conveying or carrying liquid
concrete and became a most
common equipment in
every construction sites.